Inspection Before Removal
WARNING: This page is about a different car, the 2018 Nissan Titan XD. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
During regeneration, exhaust gas temperature can reach 800°C (1500°F), and exhaust system surface temperature can exceed 700°C (1300°F), which is hot enough to ignite or melt common materials, and to cause serious personal injury. The exhaust and exhaust components can remain hot after the vehicle has stopped moving. To avoid the risk of fire, property damage, burns or other serious personal injury, allow the exhaust system to cool before beginning this procedure or repair and make sure that no combustible materials are located where they are likely to come in contact with hot exhaust or exhaust components.
CAUTION:
To avoid possible damage to the exhaust system and components, do not use the flow test portion of CONSULT Diesel Exhaust Fluid (DEF) Dosing Unit Override Test to check the system for leaks.
NOTE:
DEF deposits could possibly be left over from a previous DEF spill or repair. Verify active leaks before replacing any components.
- Inspect the area around the DEF line connection location at the DEF dosing valve.
- Inspect for signs of leaks and/or white deposits. Inspect the body and around the base of the DEF dosing valve. Check for signs of exhaust leaks and white deposits.
- If mud is found in the dosing valve body, use water to wash it off.
- A DEF leak in this area may derive from:
- The connection between the DEF line and the DEF dosing valve
- The DEF dosing valve joints between the valve and the decomposition tube
- Due to deposit buildups possibly masking the source of the leak, it may be necessary to remove the deposits and clean the area with warm water.